Polymeric yellow colorant

ABSTRACT

A group of water-soluble polymeric yellow colors and their preparation is disclosed. These colors comprise a plurality of units of a chromophore of the formula ##STR1## wherein M +  is a pharmaceutically acceptable monovalent cation attached directly to amine units present in a nonchromophoric polymer backbone. In a preferred embodiment of the invention the backbone is a homopolymer or copolymer of vinylamine. These colorants find special utility as nonabsorbable colorants for edibles, especially foods and beverages, where their yellow hue is an excellent color match for existing monomeric azo food colors such as tartrazine, and as components of acid-insoluble pigment lakes which are themselves suitable for use in edibles.

This is a continuation, of application Ser. No. 786,310, filed Apr. 11,1977, now abandoned, which in turn is a continuation-in-part of Ser. No.748,575, filed Dec. 8, 1976, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to new polymeric colorants which find especialutility as yellow food colors.

2. The Prior Art

FD&C Yellow #5, a monoazo dye of the formula ##STR2## commonly known astartrazine, has a "lemon yellow" hue which has placed it among the threemost widely used colors in foods, drugs and cosmetics. It finds usealone in gelatin desserts, jellies, beverages and the like and as acomponent of orange through green blends for use in both edibles andnonedibles.

The past decade has seen a sustained attack on the general class ofmonoazo food colors. A number of these materials, most notably Reds No.2 and No. 4, have been found to be unsafe and banned from food use bygovernmental action. There is continuing questioning of the safety ofthe monoazo colorants which is causing a search to be made for properlyhued, safe replacements. In the case of tartrazine, certain naturalcarotinoid colors can function as replacements. However, the carotinoidsare relatively very expensive. The present invention seeks to provide anonazo color replacement for the yellow colorant tartrazine. Thisinvention concerns a limited class of polymeric nitrosulfanilic acidcolorants. The advantage of polymeric colorants in food coloringapplications is disclosed in general terms in U.S. Pat. No. 3,920,855,issued Nov. 18, 1975 to Dawson et al., in copending United States Patentapplication, Ser. No. 520,530, filed Nov. 4, 1975, by Gless et al. nowU.S. Pat. No. 4,018,826, and in Japanese Patent Applications of Tanabe,such as 41-14433, 41-14434, and 41-13382. These references show thatwhen colorants are employed in polymeric form having a molecular sizeexceeding a certain limit--usually a molecular size of greater than1,000 or 2,000 daltons--and if the color compounds do not break down inuse, and thus maintain this size, the polymeric colorants are notabsorbed through the walls of the gastrointestinal tract. This meansthat when such colorants are ingested, they pass essentially directlythrough the gastrointestinal tract. They are not taken through the tractwalls into the body or its systemic circulation. Thus, risk of systemictoxicity is reduced or eliminated. The present invention is an extensionof these prior art disclosures and involves a family of polymericcolorants having particularly attractive color properties.

STATEMENT OF THE INVENTION

The new and useful polymeric colorants of this invention arecharacterized as having a nonchromophoric organic backbone of molecularweight 1,000 to 200,000 daltons to which is covalently attached throughamine groups a plurality of chromophore units of the formula ##STR3##wherein M⁺ is a pharmaceutically acceptable monovalent ion preferablyselected from K⁺, Na⁺ and NH₄ ⁺. The amine group is immediately adjacentto the chromophore aromatic ring and bonded thereto with acarbon-nitrogen single bond, thus achieving a nitrosulfanilic acidstructure ##STR4## The preparation and use in food of these materials isalso shown herein. The use of these materials in acid-insolublepigments, themselves useful in foods, is also shown.

DETAILED DESCRIPTION OF THE INVENTION

The colorant compositions of this invention comprise a plurality ofunits of a particular chromophore unit covalently bonded to a polymerbackbone through amine groups on the backbone.

The Chromophore

The chromophore employed in the colorant materials of this invention isa ##STR5## group, that is a 2-nitrobenzene-4-sulfonic acid salt. As isdemonstrated in the comparative experiments which accompany theexamples, the placement of the nitro and sulfonic acid groups in the 2and 4 position, respectively, is critical to the color desired of thesematerials. Reversing these positions or substituting otherelectronically similar groups interferes with the clear yellow colorachieved with the materials of this invention. The presence of asulfonate group on the chromophore assures that the polymeric colorantsof this invention are water soluble, that is, that they have asolubility in room temperature pH 7 water of not less than 1,000 ppm byweight. The cation of the sulfonic acid is a pharmaceutically acceptablemonovalent cation as is known to those skilled in the art. Preferredcations represented by M⁺ include Na⁺, K⁺ and NH₄ ⁺, with Na⁺ being mostpreferred.

The Backbones

The chromophores are linked into polymeric form via a nonchromophoricorganic backbone, that is, a backbone which itself does not presentvisual colors to the human eye. These backbones may be furthercharacterized as having essentially no crosslinks and as containing onlycovalent bonds which are stable under the acidic, basic, and enzymaticconditions of passage through the mammalian G.I. tract. This stabilityis required to assure that the polymeric colorants retain theirnonabsorbable size during G.I. tract passage.

Preferred backbones are carbon-nitrogen aliphatic secondary aminebackbones, carbon-oxygen aliphatic ether backbones, and essentiallylinear alkyl carbon-carbon backbones, each having molecular weights offrom about 2,000 to about 100,000 daltons. The carbon-carbon backbonesare more preferred.

Pendant from or present in the backbones are primary or lower secondaryamine groups. At least a portion of these amine groups are used to jointhe chromophore units to the backbone via a chromophore aromatic carbonto amine nitrogen single covalent bond. Such a bond is shownstructurally as ##STR6## wherein Backbone' is a linear alkyl hydrocarbonbackbone or a carbon-oxygen aliphatic ether backbone, R₂ is hydrogen ora lower alkyl, such as from 1 to 4 carbon atoms, preferably hydrogen,methyl or ethyl. The amine groups may be bonded directly to a backbonecarbon, but it is also suitable to have an organic bridge of up to 10carbon atoms in between the backbone and the amine. This organic bridgeshould be stable under the conditions of food processing and use. Thisresults in the generic structure ##STR7## wherein --C-- is a backbonecarbon and R₁ is a C to N single covalent bond, a 1 to 4 carbonalkylene, a 6 carbon arylene, a 7 to 10 carbon alkarylene, a 2 to 4carbon oxoalkylene, a 2 to 4 carbon ester, a 2 to 4 carbon amine or thelike.

Representatives of these backbone to amine structures include thestructure wherein the amine is present in the backbone ##STR8## and thefollowing structures wherein the amine is pendant from the backbone.##STR9## wherein "Chrom" is ##STR10## R₂ is as previously defined, R₇and R₈ independently are hydrogen or lower alkyls totaling at most 4carbons and R₉ is a 2 to 4 carbon alkylene. Another useful pendant linkoccurs when R₁ is a methylene and R₂ is methylene and joins to thebackbone as well in a "diallyl amine" configuration. ##STR11## Otherequivalent organic bridges may be employed as well.

Among the links the pendant amine type are preferred with the simple##STR12## (i.e., R₁ is a carbon to nitrogen single bond or a methylenelink) being more preferred. R₁ being a carbon to nitrogen single bond isthe most preferred configuration.

The backbones may contain other chemical entities as well. For example,they may contain lower alkyl (methyl or ethyl) substituents; residualamine groups, that is, amine groups which do not carry a chromophoresubstituent; and/or polar groups such as pharmaceutically acceptablecation salts, e.g., K⁺, Na⁺ or NH₄ ⁺ salts of a carboxylic acid,sulfonic acid or phosphonic acid. The polar groups, if present, canincrease the water-solubility of the colorant. The residual amine groupscan be present as amines or as acetylated amines--i.e., amides. Theacetylation of residual amines is of advantage to assure good solubilityin acidic environments and is described more fully in copending U.S.patent application Ser. No. 743,205 of Wingard et al, now U.S. Pat. No.4,169,203.

Among the colorants, those having a carbon-carbon backbone arepreferred. These are most commonly formed by polymerizing vinylamine oralkylamine or a substituted vinylamine or alkylamine as protectedprecursors or copolymerizing one of these materials with vinylsulfonate, acrylic acid, vinylphosphonate or the like. These preferredbackbones yield colorants of the structure shown in Formula I. ##STR13##wherein R₁ and R₂ are as already defined; R₃ and R₄ are hydrogen, methylor ethyl, and preferably hydrogen and A, A' and A" are independentlyselected from among the materials listed in Table I.

                  TABLE I                                                         ______________________________________                                        Residual amines                                                                                        ##STR14##                                            Acetylated residual amines                                                                             ##STR15##                                            Sulfonic acid salts                                                                                    ##STR16##                                            Carboxylic acid salts                                                                                  ##STR17##                                            Phosphonic acid salts                                                                                  ##STR18##                                            ______________________________________                                    

wherein M⁺ is as previously defined.

One of A, A' and A" may be chromophore units, ##STR19## as well so thatinstead of a four unit copolymer, a three or two unit copolymer canresult. n, m, p and q are numbers defined as follows: n+m+p+q=40 to8000; n≧0.2 (m+p+q). Preferably, R₂, R₃ and R₄ are hydrogens and R₁ is acarbon to nitrogen single bond. Among the colorants defined by FormulaI, there are four preferred types.

In the first of these preferred colorants A and A' are chromophore andA" is residual amine. Such a material may be shown as in Formula II.##STR20## wherein: M⁺ is as already defined and preferably is Na⁺ ;n+m+p+q equals 500 to 7000; and n+m+p equals 0.3 to 10 times q,preferably 1 to 7 times q, and more preferably 1.25 to 4 times q.

In the second of these preferred colorants, A is chromophore, A' isacetylated amine and A" is residual amine. Such a material may be shownas in Formula III. ##STR21## wherein M⁺ is as defined and preferably Na⁺; n+m+p+q equals 500 to 7000; n+m equals 0.3 to 10 times p+q, preferably1 to 7 times p+q and more preferably 1.25 to 4 times p+q; and q equalsfrom 0.01 to 0.2 times p and preferably from 0.02 to 0.1 times p.Colorants of this type wherein n+m equals 900 to 3500, p is 600 to 2000and q is 10 to 100 with the ratio n+m:p:q being about 6:4:0.1, i.e.,5.5-6.5:3.5-4.5:0.03-0.15 are especially advantageous.

In the third of these preferred colorants, A is polar group, especiallysulfonate, A' is chromophore and A" is residual amine. Such a materialmay be shown as in Formula IV. ##STR22## wherein M⁺ is Na⁺ or, asdefined, n+m+p+q equals 40 to 4000 and preferably 80 to 2000; n+p+qequals from 0.15 to 7 times m, preferably 0.5 to 4 times m and morepreferably 0.75 to 2.5 times m; n+p equals from 0.3 to 10 times q,preferably 1 to 7 times q, and more preferably, 1 to 3 times q.

In the fourth of these preferred colorants, A is polar group, especiallysulfonate, A' is acetylated amine, and A" is residual amine. Such amaterial may be shown as in Formula V. ##STR23## wherein M⁺ is sodium oras defined. n+m+p+q equals 40 to 4000 and preferably 80 to 2000; n+p+qequals from 0.15 to 7 times m, preferably from 0.5 to 4 times m and morepreferably from 0.75 to 2.5 times m; n equals from 0.3 to 10 times p+q,preferably from 1 to 7 times p+q, and more preferably from 1 to 3 timesp+q; and q equals from 0.01 to 0.2 times p and preferably from 0.02 to0.1 times p.

    ______________________________________                                        n equals from  150 to 500                                                     m equals from  200 to 600                                                     p equals 250 to 700                                                           9 equals        25 to 100                                                     ______________________________________                                    

and the ratio of n:m:p:q is about 5:7:8:10.5, i.e.,4.5-5.5:6.5-7.5:7.5-8.5:0.1-1.0 are especially advantageous.

Preparation

The preparation of colorants of this invention is generally carried outas follows: a preformed amine containing polymer, such as polymers ofethyleneimine, alkylamine, dialkylamine, aminostyrene,methylaminostyrene, aminoethylacrylate or vinylamine, or the like, eacheither alone or as copolymers with vinylsulfonate, vinylphosphonate,acrylic acid or methacrylic acid or the like, but especiallypolyvinylamine or copolyvinylamine/vinylsulfonate, is used as backboneand as the source of the amine groups. Representative vinylaminepolymers and copolymers and their production are disclosed in UnitedStates Patent Applications 520,530 of Gless et al., now U.S. Pat. No.4,018,826, and 638,731 of Otteson et al., now U.S. Pat. No. 4,096,134respectively, and are made a part hereof. Their preparation and thepreparation of other backbones is also shown herein in the Examples. Thechromophore is coupled to the amine backbone. This is effected verysimply by employing a derivative of the chromophore having a leavinggroup para to the sulfonic acid salt, and displacing the leaving groupwith an amine backbone nitrogen. Leaving groups known in the art may beused, with halogens, especially chloro, bromo or iodo being preferred.

This displacement reaction is carried out in liquid phase. When, as inthe preferred case where the backbone is a vinylamine polymer orcopolymer, water dissolves both the chromophore and the backbone, it isan ideal solvent. If desired, water/organic mixed solvents may be used.

The displacement is carried out in a basic environment. Base in anamount adequate to neutralize any residual acids or acidic groups on thebackbone is added at the outset of the reaction, followed by about 1equivalent, i.e., 0.5 to 10.0 equivalents, of base per equivalent ofamine present in the polymer backbone. Greater excesses of base may beused, but are not seen to offer advantage. Use of 1.0 to about 5.0equivalents of base per equivalent of amine is preferred. Anypharmacologically acceptable base which can achieve a pH of about 12 orgreater may be used. KOH and NaOH, and K₂ CO₃ and Na₂ CO₃ and mixturesthereof give good results. Preferred bases are NaOH and mixtures of NaOHand Na₂ CO₃ containing up to 3:1 molar Na₂ CO₃ to NaOH.

The concentration of reactants is most easily expressed in terms of amolarity of polymeric amine and the number of equivalents of chromophorepresent based on the amine. Polymer concentrations as low as about 0.05molar or as great as about 5 molar may be used. Lower concentrationsmight be used, but are uneconomical. Preferably, the polymer is 0.2 to 2molar. The chromophore is present in an amount of from about 0.2 toabout 3.0 equivalents, basis amine, with amounts of from about 0.5 toabout 1.5 equivalents being preferred. Clearly, the amount ofchromophore employed should not be lower than the degree of substitutiondesired.

The reaction is carried out at elevated temperatures such as reflux(100°-120° C.) with temperatures of from about 70° C. to as high as 200°C. being useful. The higher temperatures necessitate the use of suitablesuperatmospheric pressure equipment.

Reaction times range from as little as about 0.25 hours at the highesttemperature to as much as 48 hours. Degree of substitution increaseswith reaction time with 5 to 24 hours giving good reactions at 100°-120°C. Following the coupling reaction, it is often of interest to acetylateresidual amines such as by contacting the reaction mixture with from 1to 5 equivalents (basis amines) of acetic anhydride for a few minutes ata pH of 11-13 and a temperature of 0° C. to 10° C.

Following reaction (and, if used, acetylation) the polymeric colorant isrecovered and purified, such as by precipitation in a nonaqueousnonsolvent or by ultrafiltration to remove low molecular weight species.Thereafter, the colorant material is often isolated via spray-drying orthe like as a powder.

Use of Colorants

The colorants of this invention are excellent yellow colors. They areexcellent matches for tartrazine. When added in coloring amounts, suchas from 10 to 10,000 ppm wt, they color fibers and other substrates.They may be used alone or in combination with other polymeric ormonomeric colorants. They are especially advantageous as colorants foredibles since when their molecular weights are above 1,000 daltons, theyare not absorbed through the walls of the G.I. tract. In edibleapplications, the colorants are dissolved in beverages and syrups,sprayed onto or dry-mixed into powdered drink mixes and cake mixes andotherwise conventionally admixed with food beverages, pharmaceuticalsand cosmetics. The amount of color used in these applications usuallyranges from about 10 ppm wt to about 1,000 ppm wt, basis finished food,beverage or pharmaceutical.

In addition to use as "straight" soluble colors, the present yellowpolymeric dyes may be deposited alone or with other polymeric ormonomeric dyes onto the surface of particulate inorganic oxidicsubstrates, carriers or extenders to form insoluble pigments. Thesepigments, which may also be thought of as lakes, constitute anotheraspect of the present invention. The particulate substrate, carrier orextender may be classified as an inorganic oxidic material. Suchmaterials include aluminaceous solids such as alumina, e.g., high andlow activity alumina hydrate or light alumina hydrate which may take theforms Al₂ O₃.SO₃.3H₂ O or 5 Al₂ O₃.2SO₃.xH₂ O, gloss white [3BaSO₄.Al(OH)₃ ], talc, clay, silica, zinc oxide, baria, boria, titania,zirconia, magnesia, mixtures thereof, and the like. These materials arecolorless or nearly so. These materials are most easily handled aspastes or suspensions and have particle sizes of from 0.5 to 50 micronsgenerally with excellent results being achieved with particle sizes from1 to 20 microns. Aluminaceous solids, especially the alumina hydrates,are the most commonly used substrates and are preferred in the presentlakes.

The amount of colorant adsorbed onto the surface of the substrateparticle may vary from as little as 1% to as much as 75%, basis totalcolorant plus substrate weight. The amounts of dye (also known asloadings) in the higher ranges, such as from 30% to 75%, are mostunexpected as such loadings are not achieved with lakes of conventionalmonomeric dyes. Preferred loadings are from about 3% to about 50% withloadings of from about 5% to 35% being most preferred. These lakes havethe advantages of being insoluble in acids and of not bleeding in use inthe presence of salts or acids.

Lakes can be prepared by the general lake-forming reactions known in theart. One representative method is as follows.

(1) A weighed amount of alumina paste is slurried with approximately 3to 4 times its weight of deionized water.

(2) The pH of the slurry (7.9-8.0) is adjusted to pH 4.2 by the dropwiseaddition of 1:1 HCl. A calculated amount of dye (based on the solidscontent of the alumina cake) is dissolved in the minimum amount ofdeionized water and then slowly added to the alumina slurry over aperiod of 15 to 20 minutes with constant, non-shear stirring (e.g.,magnetic stirring bar or the like).

(3) During the addition of the dye and for approximately two hoursthereafter, the pH of the slurry is maintained at about 4.2 with smalladditions of 1:10 HCl.

(4) The adsorption of dye onto the alumina is followed by spotting dropsof the dispersion onto filter paper and observing bleed. Bleed is thespread of color which is due to the presence of soluble dye in theliquid phase of the dispersion. The reaction is considered terminatedwhen bleed is not observed or when further reaction does not cause bleedto diminish.

(5) Finally, the lake is filtered through a funnel and washed thoroughlywith small aliquots of deionized water. The filter cake is dried in anoven at 180° F. to constant weight, and the resulting product ground ina mortar.

The lake products essentially are insoluble pigments and may be used inpigment applications. They may be used in inks, in paints, and incolorings for edible and nonedible substrates such as frostings,candies, plastics, gelatin products, medicaments, pills and the like. Insuch uses the lakes may be present in a color imparting concentrationsuch as from 1 ppm to as much as 10,000 ppm wt, or preferably 10 to 1000ppm wt basic total composition.

The invention is further illustrated by the following Examples. Theseare given to exemplify the invention and are not to be construed aslimiting its scope.

EXAMPLE I

In Section A, acetamidoethylene monomer is prepared.

In Section B, the monomer is formed into a poly(vinylamine)hydrochloride polymer.

In Section C, the polymer of B is used as backbone to form one polymericcolorant of this invention.

In Section D, the colorant of C is acetylated to yield a secondpolymeric colorant of this invention.

A. To 2304 g of acetamide (technical) in a 12 liter reaction flask isadded 62.2 ml of 6 M aqueous sulfuric acid followed immediately by 661 gof acetaldehyde (99⁺ %). This mixture is stirred and heated until theinternal temperature reaches 78° C. (11 minutes) at which point theclear solution spontaneously crystallizes, causing a temperature rise to95° C. The reaction product, ethylidenebis-acetamide, is not separated.Heating and stirring are continued for another five minutes to atemperature of 107° C. and a mixture of 150 g calcium carbonate(precipitated chalk) and 150 g of Celite® diatomaceous earth powder isadded. A first distillate fraction of water and acetamide is removed.The remaining materials are cracked at 35 mm Hg and 185° C. A fractionmade up of vinylacetamide and acetamide is taken overhead, analyzed byNMR and found to contain 720 g of vinylacetamide and 306 g of acetamide.A portion of this pooled material is dissolved in isopropanol, cooled,and filtered to yield a stock solution.

B. An acetamidoethylene solution (8.0 moles) of Part A and2,2'-azobis-(2-methylpropionitrile) AIBN (13.3 g, 0.08 moles) in 2.13liters isopropanol is deoxygenated three times with Ar and refluxed fortwo hours. The isopropanol is removed by distillation and the polymer isthen purified of monomeric impurities and formed into an aqueoussolution. The polymer solution is concentrated to 30% w. The peakmolecular weight (M_(p) ^(PS)) is determined by gel permeationchromatography and found to be 6.0±1.5×10⁴ daltons. This method, gelpermeation chromatography, using purchased polystyrene or polystyrenesulfonate standards (porous glass bead supports) and a water or DMFeluent, is the method used to determine all experimental molecularweights given herein. A 30% aqueous polymer solution (1558 g, 505 moles)and 755 mls of 20° Be, aqueous hydrochloric acid (7.6 moles) arerefluxed for 20 hours under argon. The resultingpolyaminoethylenehydrochloride solution contains 2.05 meq/g amine and1.05 meq/g HCl (5.15 meq/g total titratable acids).

C. An aqueous solution of the polymer of Part B (4.5 moles),3-nitro-4-chlorobenzenesulfonic acid-sodium salt (Mobay Chemical-60%paste) (4.5 moles) and enough 50% w NaOH to neutralize the aminehydrochloride and residual acids (total titratable acids) isdeoxygenated three times with argon, then heated to reflux (110° C.).After one hour, 50% w NaOH (396 g, 4.5 moles) is slowly added at refluxover a six-hour period. The total time for refluxing is eight hours.

The reaction mixture is cooled by adding 8 liters cool H₂ O. One-half ofthe solution is purified by dialysis to remove salts and low molecularweight contaminants, concentrated and lyophilized to yield the polymericcolorant ##STR24## wherein n+m=100-170 and n=1.3-1.7(m).

D. The remaining one-half of the reaction product solution of Part C. isfurther cooled to 0°-5° C. by the addition of 3 kg of ice. Then, thecolorant in solution is acetylated over a 15-minute period with aceticanhydride (106 mls, 1.13 moles). Enough 25% w NaOH is gradually addedwith stirring to keep the pH=11 for the first two-thirds of theacetylation, and pH=12 for the last third. This yields the acetylatedcolorant ##STR25## wherein n+m+p=100-170 and n=1.3-1.7 (m+p). Bestvalues for these numbers indicate that the great majority of the amineshave been acetylated, i.e., m is only from 0.01 to 0.2 times p.

Both of these colorants (of Part C. and Part D.) are polymeric yellowcolorants. Each is useful as a substitute for FD&C Yellow No. 5 inedible systems. Their large polymeric size precludes their absorptionthrough the walls of the gastrointestinal tract. Thus, the chance ofsystemic toxicity is substantially reduced. The two colorants arewater-soluble. The acetylated colorant has better solubility propertiesin acidic aqueous systems.

EXAMPLE II

A smaller scale preparation of polymeric colorant is carried out. Apoly(vinylamine)hydrochloride backbone having a 5.3×10⁴ molecular weightis prepared for use as backbone using the technique of Part B of ExampleI.

Into a round-bottomed flask equipped with stirrer, argon bleed andcondenser is charged 1.0 g of the polymer, 10 mls of 1 N NaOH, 1.06 g ofNa₂ CO₃ and 2.2 g of 3-nitro-4-chlorobenzenesulfonic acid. The molaramounts are:

Polymer--10 mmol

NaOH--10 mmol

Na₂ CO₃ --10 mmol

Sulfonic Acid (As Na Salt)5 mmol

The mixture is refluxed at 150° C. for three hours and gradually cooledby dilution to 60 mls. If the colorant were recovered, it would be##STR26## wherein n+m=660; n=0.31 (n+m), i.e., 31% of the amines aresubstituted.

Instead, the colorant is acetylated by cooling to 5° C. and graduallyadding 5 mls of acetic anhydride and 5 mls of 50% NaOH over ten minutes.The product is purified by ultrafiltration using an Amicon PM-10membrane in a lab scale ultrafiltration unit. This yields a solution ofthe product ##STR27## wherein n+m+p≅660; n=0.31 (n+m+p); p≅0.1(m).

EXAMPLE III

The reaction of Example II is repeated in principle with variation of anumber of reaction parameters.

In one repeat, about 1.4 equivalents of sulfonic acid are used and thereaction is continued for 22 hours. This gives very completesubstitution of the backbone amines 90% are substituted. The remaining10% are present as amines or as acetylated amines.

In a second repeat, only 1.0 equivalents of the sulfonic acid isemployed along with 1.0 equivalents of each of Na₂ CO₃ and NaOH. Aneight-hour reaction time is used to yield a final product having 58% ofits amines substituted with chromophores. The remaining amines arepresent as amines or acetylated amines.

EXAMPLE IV

A. Acetamidoethylene solution (250 g, 1.025 moles), prepared as inExample I, Part A, is stripped to 133 mls. This material is charged to a2 liter flask equipped with stirrer, condenser and heater along with 230mls of a 25% solution (in water) of sodium vinyl sulfonate (0.552moles), 400 mls of water and 4 g of AIBN polymerization catalyst. Themixture is heated with stirring. After about 50 minutes, it reaches60°-70° C. where it is maintained for 24 hours. An additional gram ofAIBN is added and the mixture is heated for an additional 12 hours toyield a product which is precipitated in 30 volumes of IPA and dried ina vacuum oven at 125° C. for four hours. This product has a formula##STR28## and a molecular weight of about 36,000, i.e., the polymercontains on average about 220-240 units of amine and about 120-140 unitsof sulfonate. This product is then hydrolyzed to the amine salt bytreating with four equivalents of hydrochloric acid at 100°-110° C. for20-24 hours. This hydrolysis product ispoly(aminoethylene-sodiumethylenesulfonate) which is referred to hereinat times as PAE-SES.

B. Into an egg-shaped flask equipped with stirrer, reflux condenser,argon bleed and oil bath heater, is added 1.3 g (10 mmol of amine) ofthe hydrolyzed copolymer of Part A and 10 mls (10 mmol) of 1 N NaOH.After the polymer dissolves, 2.12 g (20 meq) of Na₂ CO₃ and 4.5 g (10mmol) of 3-nitro-4-chloro-benzenesulfonic acid are added, the mixture isdeoxygenated thrice and heated to 100° C. (reflux). After 24 hours, thereaction is cooled. The colorant is separated by removing the impuritiesvia ultrafiltration and lyophilizing the retentate to yield 1.8 g ofproduct of the structure ##STR29## wherein n=0.40 (n+m+p); m=0.35(n+m+p); p=0.25 (n+m+p).

C. A 0.5 g portion of the colorant of Part B is dissolved in 25 ml ofwater. At 0°-5° C., 2 mls of acetic anhydride is gradually added withstirring along with 1 N NaOH in an amount to hold the pH at 11-12. Thiscauses the formation of an acetylated product ##STR30## wherein n=0.40(n+m+p+q); m=0.35 (n+m+p+q); p=0.24 (n+m+p+q); q≦0.03 (n+m+p+q). Theproduct is recovered.

EXAMPLE V

A. The preparation of poly(N-methylvinylamine) is begun by adding 500 gof N-methylaminoethanol to 1380 g (2.20 equivalents) of acetic anhydrideat 115°-120° C. The reaction is exothermic (cooling required) and iscomplete by the time the addition is concluded. The bis-acetylatedproduct, ##STR31## is isolated by vacuum distillation (bp 95°-98°/0.1mm) as a colorless oil in about 93% yield.

The bis-acetylated product is pyrolyzed by passing 642 g of thismaterial at a rate of 1.17 g/min through a Pyrex® helices-packed quartztube (3.5 cm diameter, 40 cm length), maintained at 480°. A 400 ml/minArgon stream is employed. The crude pyrolysate is a dark orange oilweighing 1350 g. The crude mixture containing the desiredN-methylvinylacetamide is distilled (72° C./20 mm) to afford 250 g ofpurified N-methylvinylacetamide.

Polymerization of 225 g of purified N-methylvinylacetamide is carriedout in 500 ml of methanol at 70° C. in the presence of 4 mol % of AIBN.The polymerization is complete within 12 hours and affords 200 g yieldof poly(N-methylvinylacetamide).

The polymeric amide is hydrolysed with 6 N HCl at 125° to yieldpoly(N-methylvinylamine) as the hydrochloride. This material has amolecular weight of about 20,000 as determined by gel permeationchromatography comparisons to standards. The hydrolysis is monitored byNMR and requires roughly 40 hours to go to completion. The product isisolated in essentially quantitative yield by precipitation of thepartially evaporated reaction mixture from isopropanol.

B. Into a round bottomed flask, equipped with stirrer, argon bleed andcondenser, is charged 1.1 g of the polymer (10 mmole), 10 mls of 1 NNaOH, 2.12 g of Na₂ CO₃ and 2.2 g of 3-nitro-4-chlorobenzenesulfonicacid. The mixture is refluxed at ˜150° C. for six hours. One-half of themixture is cooled, diluted, ultrafiltered and lyophilized to yield thesolid colorant ##STR32##

The remaining half is cooled to 0°-5° C. with ice addition. Gradually, 3ml of acetic anhydride and ˜3 mls of 50% NaOH are added to acetylate theresidual amines. The product is isolated by ultrafiltration andlyophilization. It has the structure ##STR33##

EXAMPLE VI

The preparation of Example IV is repeated substituting an equimolaramount of acrylic acid for the vinyl sulfonate in the preparation of thepolymer backbone. A 1:1 ratio of acrylic acid to amine is employed. Thisproduct would have a molecular weight of from 1.0×10⁴ to 5.0×10⁴daltons. This product could be employed as a backbone for a polymericcolorant of this invention, prepared in accord with Example IV, having astructure ##STR34## With acetylation, the residual amines could beconverted, in 90+% efficiency, to acetamides.

EXAMPLE VII

The preparation of Example IV is repeated. A different ratio of amine tosulfonate in the polymer backbone is achieved by adding vinyl sulfonateand acetamidoethylene in a 1:3 molar ratio. The resulting polymer is aPAE-SES copolymer having a 3 to 1 nitrogen to sulfur molar ratio and amolecular weight of 2.0-5.0×10⁴ daltons. When this material issubstituted in the colorant preparation of Example IV, a similarproduct, with similar chromophore substitution, results. Residual aminegroups can be acetylated, if desired.

EXAMPLE VIII

Poly(aminostyrene) ##STR35## having a molecular weight greater than 1000is obtained from Polysciences, Inc. This material could be employed as abackbone in the preparation of a colorant of this invention.

Into a round bottomed flask, equipped with a stirrer, condenser, argonbleed and oil bath heater, is added 1.2 g (10 mmol of amine) of thispolymer, 10 mls of 1 N NaOH, and 10 mls of pyridine and this mixture isstirred until the polymer goes into solution. Then, 2.12 g (20 meq) ofNa₂ CO₃ and 6.75 g (15 mmol) of 3-nitro-4-chlorobenzenesulfonic acid areadded, the mixture is deoxygenated and heated to reflux. After 24 hoursthe mixture is cooled. The polymeric colorant having the formula##STR36## separated. Impurities are removed by ultrafiltration and theproduct is lyophilized. If desired, the residual amines could beacetylated to amides using the general method of Part D of Example I.

EXAMPLE IX

Linear poly(ethyleneimine) ##STR37## having a molecular weight above1000 daltons, is obtained using the method of Saegusa et al.(Macromolecules, Vol. 5 (1972) page 108), and could be employed as abackbone in the preparation of a polymeric colorant.

Into a round bottomed flask, equipped with a stirrer, condenser, argonbleed and oil bath heater, is charged 0.45 g (10 mmol) of thepoly(ethyleneimine), 20 mls of 1 N NaOH (20 mmol), 2.12 g of Na₂ CO₃ (20mmol), and 13.5 g (30 mmol) of 3-nitro-4-chlorobenzenefulfonic acid. Themixture is deoxygenated, heated to reflux and then stirred overnight,and thereafter cooled. The polymeric colorant product ##STR38##recovered, purified by ultrafiltration and lyophilized. If desired, theresidual amines could be acetylated to amides using the general methodof Part D of Example I.

EXAMPLE X

In Examples I-IX, all salts are sodium salts, since the bases used intheir preparation are sodium bases. It will be appreciated that bysubstituting corresponding potassium bases in the preparations,potassium salts could be formed. Similarly, ammonium cations, or otherpharmaceutically acceptable cations, can be substituted in the products.

EXAMPLE XI

A lake is prepared from the polymeric yellow colorant of Example I.Aluminum hydroxide, wet gel (44.8 g), is dispersed in 225 ml distilledwater with a magnetic stirrer. This amount of wet gel, by analysis, isshown to contain 8.0 g of Al₂ O₃ and 36.8 g of water. Hydrochloric acid1:1 concentration is dripped in until the solution pH is 4.0 by pHelectrode measurement. The colorant of Example I, 2.0018 g, is dissolvedin 200 ml of distilled water. The solution of colorant is graduallyadded to the rapidly stirring suspension of aluminum hydroxide. The pHis held at 4.2-4.3. The polymeric colorant is adsorbed onto the surfaceof the aluminum hydroxide. Initially, only part of the dye is adsorbedsuch that a drop of the suspension on filter paper causes a deposit ofcolored solid (lake) at the center and a colored "halo" of dissolvedcolorant. After stirring for about an hour, the colorant is completelyexhausted onto the alumina and the "halo" is colorless. The lake productis calculated to contain 20% (basis total weight of lake) of color. Thelake is recovered by filtration, washed and spread to dry in pans in anoven at 120° C. When dry, the lakes are lumpy and agglomerated. Grindingproduces the desired pigment-like powder. This lake is a bright yellow.It has the advantageous properties of being insoluble in acid and of notbleeding in acid.

EXAMPLE XII

The lake preparation of Example XI is repeated four times varying theamount of colorant solution employed. In the first repeat, 400 ml ofsolution is used, thus yielding a final product containing 33% colorantand having a darker shade than the lake of Example XI. In the secondrepeat, 600 ml of solution is used, yielding a yet darker orange productcontaining 43% colorant. In the third repeat, 100 ml of solution isused, yielding a lighter yellow lake containing 11% colorant. In thelast repeat, 50 ml of colorant is used, yielding a light yellow 5.5% wcolorant lake.

EXAMPLE XIII

The lake preparation of Example XI is repeated with one change. Insteadof the colorant of Example I, a mixture of 1.5 g of the colorant ofExample I and 0.5 g of a polymeric red colorant of the formula ##STR39##is employed. This results in a bright red-orange lake product which hasthe same advantageous properties observed with the lake of Example XI.

EXAMPLE XIV

The lake preparation of Example XI is repeated three times, each timevarying the inorganic oxidic substrate. First, finely divided titania,(titanium dioxide) is used. Second, finely divided zirconia is used.Finally, silica is used. In each case, a lake is formed which is similarin character to the lake of Example XI.

COMPARATIVE EXPERIMENTS

A. A polymeric colorant is prepared using as chromophore a positionalisomer of the material used in the present invention. Into a 50 mlflask, equipped with stirrer and argon bleed, is placed 0.9 g (9.5 mmol)of poly(aminoethylene) as used in Example I, 10 mls of water and 2.65 g(25 mmol) of Na₂ CO₃. After deaerating the mixture, it is stirred andheated to 70° C. The chromophore, ##STR40## is added (1.19 g, 5.0 mmol)and the mixture is kept at 98°-100° C. for about 18 hours. Three dropsof 50% NaOH and 10 ml of water are added during the reaction. Theproduct is removed and ultrafiltered. A portion is acetylated andultrafiltered, as shown in Example I.

This product (acetylated) has a structure very close to that of thecolorants of the invention, i.e., ##STR41##

When the color of this material is evaluated, it is seen to beunacceptable as a replacement for existing food colors. It has a veryweak greenish-yellow color. Colors of this invention, such as producedin Example I, do not have this failing.

B. A second similar colorant is produced. A 50 ml flask, equipped withstirrer and argon bleed and condenser, is charged with 1.0 g (7.7 mmol)of PAE-SES copolymer such as shown in Example IV. Na₂ CO₃ (3.25 g, 31mmol) and 20 ml water are added. The mixture is heated to 95° C. and1.55 g (7.7 mmol) of chromophore ##STR42## is added with 10 ml of water.The mixture is refluxed ˜100° C. for about 20 hours, cooled, filteredthrough glass filter A, ultrafiltered and lyophilized to yield ##STR43##

This product is evaluated as a yellow colorant. It is observed to have avery low coloring power (tinctorial strength). This property isquantitized by the color's absorptivity. The material has anabsorptivity of 3.9. Compounds of the invention are higher, havingabsorptivities of 13-16 in most cases.

USE OF COLORANTS

Colorants prepared in the preceding Examples may be employed as colorsfor edible materials.

A. A "lemon" soft drink beverage powder is prepared.

The color of Example I, 15 g is dissolved in deionized water to form ayellow color solution. Next, 81 kg of dry granulated sugar (sucrose),20-100 mesh, is tumbled in a ribbon blender. The color solution is thensprayed onto the surface of the tumbling sugar particles over 1-3minutes. The tumbling is continued for another 1-3 minutes to uniformlycolor the sugar particles. Then, a very finely ground powdereddessicant, anhydrous calcium phosphate, may be added to the tumblingsugar to dry the yellow color onto the surface of the sugar particles.No more than about 500 g of dessicant is required. Alternatively, 30° C.dry air may be blown through the blender for a few minutes to dry thesugar particles. The mixture is a free flowing powder. Then, two minutesafter phosphate addition, the following components are added to themixer as 20-100 mesh dry powders.

3 kg of dried gum arabic clouding agent,

5 kg of citric acid,

0.5 kg of ascorbic acid,

1 kg of sodium citrate,

1.5 kg of a solidified emulsion of lemon oil in corn syrup solids.

This combination is tumbled for an additional ten minutes and packagedin water vapor impermeable envelopes. When 80 grams of this product areadded to 950 ml of water, a light yellow colored lemonade-typenoncarbonated beverage is obtained.

B. The preparation of A. is repeated with two changes. In place of the15 g of the color of Example I, a mixture of 30 g of that color with 10g of monomeric FD&C Red No. 40 is employed in the first repeat. Orangeoil is substituted for lemon oil. This blend of yellow of this inventionwith an FD&C dye results in a mixture which, upon addition to water,yields an orangeade style beverage.

C. The preparation of B. is repeated with one change; in place of 10 gof Red No. 40, 15 g of a polymeric red dye of the formula ##STR44##prepared in accord with the teachings of USSN 751,856 of Bunes isemployed. This blend of a yellow of this invention with anotherpolymeric dye yields a very suitable orange colored beverage mix which,upon addition to water, produces an orangeade style beverage.

D. The colors of this invention find use in dietetic foods and beverageswhere their nonabsorbability properties present the bonus of imparting anoncaloric property to the colors as well. A dietetic orange beverageconcentrate is prepared. First, a colored bulking agent is formed bydissolving 10 kg of corn syrup solids, 100 g of sodium saccharin, 30 gof the yellow of Example II and 3 g of the polymeric red used inpreparation C. in water and spray-drying. This yields a dry solid. Thissolid (6.5 kg) is charged to a laboratory scale V blender and tumbled.The yellow and red colors are firmly fixed into the bulking agent and donot segregate. The following other materials are added and tumbled.

    ______________________________________                                        Citric Acid              1300   g                                             Clouding agent - hydrogenated                                                 vegetable oil            500    g                                             Sodium carboxymethylcellulose                                                                          500    g                                             Ascorbic Acid            200    g                                             Sodium Citrate           200    g                                             Orange Flavor, including                                                      Firmenich Imit. Orange Flavor                                                 59,427/AP                                                                     Perma Stable Orange Flavors                                                   6007 and 6032                                                                 Fries and Fries Art. Orange Flavors                                           11736 and 11169          750    g                                             ______________________________________                                    

These materials dry-blend into the bulking agent. When this blendedproduct is dissolved in water at a concentration of about 4%, it yieldsa noncarbonated dietary orange beverage. When it is dissolved incarbonic acid-saturated water at a level of 3.0%, an orange-coloredcarbonated drink results.

E. The colors are used in the preparation of a yellow colored lemonflavored instant pudding/pie filling powder. Quick hydrating dextrose(20 kg) is added to a ribbon type blender, then 175 g of lemon extract,100 g of the polymer color of Example IV, and 50 g of vanillin areblended in. The color may be added as a fine (50-200 mesh) powder or asa solution in a minimum amount of water. Then, in sequence, 50 kg ofgranulated sugar, 1 kg of salt and 33 kg of pregelled modified waxycornstarch are added. The mixture is blended for 15 minutes and packagedin 4 oz packages. In use, one package is added to a pint of milk whilestirring until a smooth thick lemon-yellow colored pudding results (3-5minutes).

F. The colors are used in baked on coating mixes. First, a concentratedsolution of 30 parts of the color of Example I and 1 part of FD&C Red#40 is prepared and gradually added to 200 parts of granulated sugartumbling in a blender. Warm (30° C.) dry air is passed through thetumbling mass to remove water and form a dry colored sugar powder. Thispowder is used in the following coating mix.

    ______________________________________                                        Component           Percent by Weight                                         ______________________________________                                        Flour               15                                                        Bread crumbs        57.75                                                     Salt                7                                                         Monosodium glutamate                                                                              1                                                         Herbs and spices    1                                                         Solid fat powder    15                                                        Calcium phosphate   3                                                         Color powder        0.25                                                      ______________________________________                                    

This mixture (150 g) is placed in a plastic bag. Uncooked chickenpieces, previously dipped in milk, are added to the bag, shaken with thecoating mix, removed, placed in a single layer on a cookie sheet andbaked for 50 minutes at 400° F. The coating mix employing the color ofthis invention imparts a uniform golden "simulated deep fried" color tothe chicken as it bakes.

G. The colors of this invention are used in prepared snack foods. Rawcorn meal (100 kg), cottonseed oil (6.5 kg), water (7.5 kg) and color ofExample I (25 g) are mixed together in a blender until homogeneous.Then, 10 kg of dehydrated cheddar cheese, 500 g of salt, 250 g ofmonosodium glutamate are added and blended into the mixture. The mixtureis then shoveled into the hopper of an extruder and extruded through a 1cm orifice. The orifice is elongated and heated to 130° C. so that thewater in the mixture vaporizes and puffs the mixture as it is extruded.The extrudate is cut into 4 cm pieces and baked at 160° C. for 15-20minutes. After baking, the resulting cheese flavored-cheese coloredsnacks are dusted with 1% w salt and packaged.

H. Using the techniques of preparation G., but altering the compositionof the feed mixture, and the shape of the extruder dye to compositionsand shapes more appropriate for puffed breakfast cereals, the polymericyellow colors of this invention are incorporated into presweetened andnonpresweetened breakfast cereals.

I. The yellow color of this invention prepared in Example II isdissolved in distilled water at a 2% level. This solution is packagedfor use as a food coloring for frostings, cakes, decorated eggs andother home uses.

J. Using the methods of spraying a solution of color onto sugar grainsshown in preparation A., a color of this invention is added to sugarwhich, in turn, is used as a component in a powder for makinglemon-flavored gelatin desserts.

K. The polymeric colorant of Example I is used to color gelatin capsulesfor medicaments. USP gelatin is dissolved in water with heating. Thecolorant of Example I, 300 ppm (basis weight of gelatin is added. Thecolored gelatin solution is then formed into yellow capsules by methodsknown to the art.

L. The polymeric lake of Example XI is employed in a pill coating. USPgelatin is dissolved in water and evaporated to give a solution theconsistency of light cream. The lake of Example IX, 200 ppm basis weightof gelatin, is then suspended in the gelatin solution. Ascorbic acidtablets and aspirin tablets are covered with this yellow suspension andquickly dried to obtain shiny yellow coated tablets.

M. The polymeric lake of Example XI is used as a component of cosmetics.It is blended and ground with red lakes and brown lakes. Ten parts ofthis blend of lake are then added to a melt composed of 15 partsbeeswax, 4 parts petrolatum, 55 parts semihydrogenated castor oil, 10parts paraffin oil, and 4 parts lanolin. This mixture is stirred andcompounded on a heated roller mill and placed in containers. It servesas an anhydrous cream rouge.

N. The polymeric lake of the third preparation of Example XII isemployed as a coloring in frosting. Margarine (500 g) is placed in amixer, followed by 0.5 g of the lake of preparation 3 of Example X as afine (100% passes 300 mesh) powder. The lake is thoroughly blended intothe margarine. Then, 4 kg of confectioners sugar, 30 ml of imitationvanilla extract, 30 g of salt, and 5 ml of banana flavoring are added tothe mixture and slowly blended with the margarine. Water is graduallyadded until a spreadable coherent mass of yellow colored banana-flavoredfrosting is obtained.

O. The polymeric colorant of Example VIII is used as a colorant for adetergent based shampoo.

    ______________________________________                                        Fatty acid-protein condensation                                               products                30%                                                   Triethanolamine lauryl sulfate                                                                        20%                                                   Sodium alginate (3% solution)                                                                         5%                                                    Glycerol                3%                                                    Water                   42%                                                   Color of Example VIII   100 ppm                                               ______________________________________                                    

are combined in a blender and mixed until homogeneous. This yields ayellow-colored shampoo product employing the colorant of this invention.

What is claimed is:
 1. A polymeric yellow colorant soluble in roomtemperature pH 7 water to an extent of not less than 1,000 ppm byweight, and comprising (1) an amine containing, nonchromophoric,essentially linear backbone polymer, said backbone polymer having amolecular weight of from 1,000 to 200,000 daltons and (2) a plurality ofchromophores covalently depending from the amine moieties of saidbackbone polymer, said chromophores having the basic nucleus: ##STR45##wherein M⁺ is a pharmacologically acceptable cation, and said pendantchromophores being directly covalently linked to said backbone polymerthrough the amine moieties thereof via an aromatic carbon-nitrogensingle bond and defining a nitrosulfanilic acid structure therewith. 2.The polymeric yellow colorant as defined by claim 1, said plurality ofchromophores (2) ranging from between 10 and
 2000. 3. The polymericyellow colorant as defined by claim 2, said backbone polymer being apolymer of vinylamine.
 4. The polymeric yellow colorant as defined byclaim 3, said backbone polymer being homopolyvinylamine.
 5. Thepolymeric yellow colorant as defined by claim 1, consisting essentiallyof recurring units of the structural formula: ##STR46## wherein A, A'and A" are independently selected from the group consisting of:##STR47## and further wherein n, m, p and q are numbers such that thesum of n, m, p and q is from 40 to 8000 and n is not less than 0.2 timesthe sum of m+p+q.
 6. The polymeric yellow colorant as defined by claim5, wherein A, A' and A" are independently selected from the groupconsisting of: ##STR48##
 7. The polymeric yellow colorant as defined byclaim 1, consisting essentially of recurring units of the structuralformula: ##STR49## wherein n, m, p and q are numbers such that the sumof n, m, p and q is from 40 to 8000 and n is not less than 0.2 times thesum of m+p+q, and wherein n+m+p is from 0.3 to 10 times q.
 8. Thepolymeric yellow colorant as defined by claim 1, consisting essentiallyof recurring units of the structural formula: ##STR50## wherein R₂ ishydrogen or lower alkyl having from 1 to 4 carbon atoms and R₃ and R₄are independently hydrogen, methyl or ethyl wherein n, m, p and q arenumbers such that the sum of n, m, p and q is from 40 to 8000 and n isnot less than 0.2 times the sum of m+p+q, and wherein n+m is from 0.3 to10 times p+q and q is from 0.01 to 0.4 times p.
 9. The polymeric yellowcolorant as defined by claims 7 or 85, wherein n+m+p+q is from 500 to7000, and n+m+p is from 1 to 7 times q.
 10. The polymeric yellowcolorant as defined by claim 9, wherein n+m+p is from 1.25 to 4 times q.11. The polymeric yellow colorant as defined by claim 1, consistingessentially of recurring units of the structural formula: ##STR51##wherein R₂ is hydrogen and R₃ and R₄ are independently hydrogen, whereinn, m, p and q are numbers such that the sum of n, m, p and q is from 80to 2000 and n is not less than 0.2 times the sum of m+p+q, and whereinn+p+q equals from 0.5 to 4 times m and n+p equals from 1 to 7 times q.12. The polymeric yellow colorant as defined by claim 1, consistingessentially of recurring units of the structural formula: ##STR52##wherein R₂ is hydrogen or lower alkyl having from 1 to 4 carbon atomsand R₃ and R₄ are independently hydrogen, methyl or ethyl, wherein n, m,p and q are numbers such that the sum of n, m, p and q is from 80 to2000, n+p+q equals from 0.5 to 4 times m, n equals from 1 to 7 timesp+q, and q equals from 0.02 to 0.1 times p.
 13. The polymeric yellowcolorant as defined by claim 1, consisting essentially of recurringunits of the structural formula, ##STR53## wherein n is a number from150 to 500, m is a number from 200 to 600, p is a number from 250 to 700and q is a number from 25 to 100, such that n:m:p:q are in a ratio ofabout 5:7:8:10.5.
 14. The polymeric yellow colorant as defined by claims8 or 12, wherein each R₃ and R₄ is hydrogen.
 15. The polymeric yellowcolorant as defined by claim 14, wherein each R₂ is hydrogen.
 16. Thepolymeric yellow colorant as defined by claim 2, said backbone polymerhaving essentially no crosslinks.
 17. The polymeric yellow colorant asdefined by claim 2, said backbone polymer comprising only covalent bondsstable under the conditions of the mammalian gastrointestinal tract. 18.The polymeric yellow colorant as defined by claim 2, said backbonepolymer being selected from the group consisting of carbon-nitrogenaliphatic secondary amine backbone polymer; carbon-oxygen aliphaticether, pendant amino group backbone polymer; alkyl carbon-carbon,pendant amino group backbone polymer; and copolymers thereof.
 19. Thepolymeric yellow colorant as defined by claim 18, said backbone polymerhaving a molecular weight of from about 2,000 to 100,000 daltons. 20.The polymeric yellow colorant as defined by claim 19, said backbonepolymer being an essentially linear alkyl carbon-carbon backbonepolymer.
 21. The polymeric yellow colorant as defined by claim 3, saidbackbone polymer being a copolymer of vinylamine with a comonomerselected from the group consisting of vinyl sulfonate, acrylic acid,methacrylic acid and vinylphosphonate.
 22. The polymeric yellow colorantas defined by claim 2, said backbone polymer being a polymer ofethyleneimine.
 23. The polymeric yellow colorant as defined by claim 1,consisting essentially of recurring units of the structural formula:##STR54## wherein n, m, p and q are numbers such that the sum of n, m, pand q is from 40 to 8000 and n is not less than 0.2 times the sum of m,p and q.
 24. The polymeric yellow colorant as defined by claim 2, saidbackbone polymer being a polymer of lower alkylamine.
 25. The polymericyellow colorant as defined by claim 2, said backbone polymer being apolymer of dilower dialkylamine.
 26. The polymeric yellow colorant asdefined by claim 2, said backbone polymer being a polymer ofaminoethylacrylate.
 27. The polymeric yellow colorant as defined by anyof claims 2, 5, 7, 8, 11 or 12, wherein M⁺ is selected from the groupconsisting of Na⁺, K⁺ and NH₄ ⁺.
 28. The polymeric yellow colorant asdefined by claim 27, wherein M⁺ is Na⁺.
 29. The polymeric yellowcolorant as defined by claim 1, the amine moieties comprising said aminecontaining, nonchromophoric, essentially linear backbone polymer beingsecondary amine groups present and directly covalently bonded withinsaid backbone polymer.
 30. The polymeric yellow colorant as defined byclaim 1, the amine moieties comprising said amine containing,nonchromophoric, essentially linear backbone polymer being primary aminegroups pendant from said backbone.
 31. The polymeric yellow colorant asdefined by claim 1, the amine moieties comprising said amine containing,nonchromophoric, essentially linear backbone polymer being secondaryamine groups pendant from said backbone.
 32. The polymeric yellowcolorant as defined by claim 29, containing residual,non-chromophore-substituted secondary amine groups present and directlycovalently bonded within said backbone polymer.
 33. The polymeric yellowcolorant as defined by claims 30 or 31, containing residual,non-chromophore-substituted secondary amine groups pendant from saidbackbone.
 34. The polymeric yellow colorant as defined by claim 32, atleast a portion of said residual, non-chromophore-substituted aminegroups being acetylated.
 35. The polymeric yellow colorant as defined byclaim 1, said backbone polymer comprisingcopolyvinylamine/vinylsulfonate.
 36. The polymeric yellow colorant asdefined by any of claims 1, 3, 18, 29, 30, 31, 32, or 34, said backbonepolymer further containing water-solubilizing polar groups.
 37. Thepolymeric yellow colorant as defined by claim 30, said backbone polymerbeing homopolyvinylamine.
 38. The polymeric yellow colorant as definedby claim 37, containing residual, non-chromophore-substituted primaryamine groups, at least a portion of said residual groups beingacetylated.
 39. The polymeric yellow colorant as defined by claims 29 or32, said backbone polymer being polyethyleneimine.
 40. The polymericyellow colorant as defined by claim 32, said backbone polymer beingpolyethyleneimine and at least a portion of said residual,non-chromophore-substituted secondary amine groups being acetylated. 41.The polymeric yellow colorant as defined by claims 30 or 31, or saidamine groups being pendant to the backbone polymer through a 1 to 4carbon alkyl bridge.
 42. The polymeric yellow colorant as defined byclaims 30 or 31, said amine groups being pendant to the backbone polymerthrough a 2 to 4 carbon carboxylate ester bridge.
 43. The polymericyellow colorant as defined by claims 30 or 31, said amine groups beingpendant to the backbone polymer through a 2 to 4 carbon alkyl etherbridge.
 44. The polymeric yellow colorant as defined by claims 30 or 31,said amine groups being pendant to the backbone polymer through a 2 to 4carbon alkyleneamine bridge.
 45. The polymeric yellow colorant asdefined by claim 33, at least a portion of said residual,non-chromophore-substituted amine groups being acetylated.
 46. Thepolymeric yellow colorant as defined by claim 33, said backbone polymerfurther containing water-solubilizing polar groups.
 47. The polymericyellow colorant as defined by claim 1, consisting essentially ofrecurring units of the structural formula: ##STR55## wherein n+m is anumber from 900 to 3500, p is a number from 600 to 2000, and q is anumber from 10 to 100, n+m, p and q being further defined as being in aratio of about 6 to 4 to 0.1.